refactor: move plugin loading into typed registry

src/trx-client/trx-frontend/trx-frontend-http/frontend/build.mjs

@@ -19,6 +19,7 @@ await build({
     app: path.join(sourceDir, "app.js"),
     "ui-core": path.join(sourceDir, "ui-core.ts"),
     "map-core": path.join(sourceDir, "map-core.js"),
+    "plugin-loader": path.join(sourceDir, "plugin-loader.ts"),
     screenshot: path.join(sourceDir, "screenshot.ts"),
     "webgl-renderer": path.join(sourceDir, "webgl-renderer.ts"),
     ais: path.join(sourceDir, "plugins", "ais.js"),

src/trx-client/trx-frontend/trx-frontend-http/frontend/src/plugin-loader.ts

@@ -0,0 +1,68 @@
+// SPDX-FileCopyrightText: 2026 Stan Grams <sjg@haxx.space>
+//
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+type PluginGroup = "digital-modes" | "map-data" | "map" | "statistics" | "bookmarks" | "recorder" | "settings";
+
+const pluginGroups: Readonly<Record<PluginGroup, readonly string[]>> = {
+  "digital-modes": ["/ft8.js", "/ft4.js", "/ft2.js", "/wspr.js", "/cw.js", "/background-decode.js", "/sat.js", "/wefax.js"],
+  "map-data": ["/map-core.js", "/ais.js", "/vdes.js", "/aprs.js", "/hf-aprs.js"],
+  map: ["/map-core.js", "/ais.js", "/vdes.js", "/aprs.js", "/hf-aprs.js", "/sat.js", "/sat-scheduler.js"],
+  statistics: ["/map-core.js"],
+  bookmarks: ["/bookmarks.js"],
+  recorder: [],
+  settings: ["/vchan.js", "/scheduler.js"],
+};
+
+const loaded = new Set<string>();
+const loading = new Map<string, Promise<void>>();
+const modulePlugins = new Set(["/ft8.js", "/ft4.js", "/ft2.js", "/wspr.js", "/cw.js"]);
+
+function loadLegacyScript(path: string): Promise<void> {
+  return new Promise((resolve, reject) => {
+    const script = document.createElement("script");
+    script.src = path;
+    script.addEventListener("load", () => { resolve(); }, { once: true });
+    script.addEventListener("error", () => { reject(new Error(`Failed to load plugin script: ${path}`)); }, { once: true });
+    document.body.appendChild(script);
+  });
+}
+
+async function loadPlugin(path: string): Promise<void> {
+  if (loaded.has(path)) return;
+  const pending = loading.get(path);
+  if (pending) return pending;
+  const request = (modulePlugins.has(path) ? import(path).then(() => undefined) : loadLegacyScript(path)).then(() => {
+    loaded.add(path);
+    loading.delete(path);
+  }).catch((error: unknown) => {
+    loading.delete(path);
+    throw new Error(`Failed to load plugin module: ${path}`, { cause: error });
+  });
+  loading.set(path, request);
+  return request;
+}
+
+async function loadPlugins(group: string): Promise<void> {
+  if (!(group in pluginGroups)) return;
+  for (const path of pluginGroups[group as PluginGroup]) await loadPlugin(path);
+}
+
+function requestPlugins(group: string): void {
+  void loadPlugins(group).catch((error: unknown) => { console.error(error); });
+}
+
+const loaderWindow = window as typeof window & {
+  loadEagerPlugins?: () => Promise<void>;
+  loadPluginsForTab?: (tab: string) => Promise<void>;
+};
+loaderWindow.loadEagerPlugins = async () => {
+  await Promise.all(["digital-modes", "map-data", "bookmarks", "settings"].map(loadPlugins));
+};
+loaderWindow.loadPluginsForTab = loadPlugins;
+
+document.addEventListener("click", (event) => {
+  if (!(event.target instanceof Element)) return;
+  const tab = event.target.closest<HTMLElement>("[data-tab]")?.dataset.tab;
+  if (tab) requestPlugins(tab);
+});

src/trx-client/trx-frontend/trx-frontend-http/frontend/tests/smoke.test.mjs

@@ -11,6 +11,8 @@ const indexPath = new URL("../../assets/web/index.html", import.meta.url);
 test("index loads the shared UI before the application", async () => {
   const html = await readFile(indexPath, "utf8");
   assert.ok(html.indexOf("/ui-core.js") < html.indexOf("/app.js"));
+  assert.ok(html.indexOf("/plugin-loader.js") < html.indexOf("/app.js"));
+  assert.equal(html.includes("var pluginScripts"), false);
 });
 
 test("startup has no remote script or stylesheet dependencies", async () => {